Method for projecting streams



1949 R. L. LUCE 2,489,097

METHOD FOR PROJECTING STREAMS Filed Jan. 30, 1947 AJI'I/ f9 JzZ/yeazz J?m,

Patented Nov. 22 1949 FQR PRQJECTING STREAMS Roy L. Luce, Chicago, Ill

Blast Corporation, of Illinois assignor to Hydro- Chicago, lit, acorporation Application January 30, 194 7, Serial No. 725,250

(Cl. l--282) 3 Claims.

This invention relates to method for projecting liquid streams and moreparticularly to the projection of liquid, which may or may not containabrasive material in suspension, in the form of an unbroken highvelocity jet.

In many operations, as in liquid sandblasting hydraulic mining, and thelike, it is desirab project streams of liquid through substanti l otances without having the jets break-up droplets or spray. With a plainnozzle, it 1' been found that the liquid jet tends to breakup or fuzzinto a series of disconnected droplets or into a relatively fine spraywithin a short dis tance of the nozzle. A broken jet of this type i farless effective in liquid blasting or other hydraulic cutting operationsthan an unbroken stream.

It is one of the objects of the present invention to provide a method ofprojecting liquid strean in which air is added to the stream to beentrained thereby shortly before the final discharge of the stream.

Another object is to provide a method of pro jecting liquid streams inwhich the stream passed through an auxiliary nozzle prior to its finaldischarge and has air added thereto immediately prior to its entranceinto the auxiliary nozzle.

Still another object is to provide a method of projecting abrasivematerial with liquid in which abrasive material is first added to theliquid air is subsequently entrained by the liquid prior to itsdischarge.

The above and other objects and advantages of the invention will be morereadily apparent from the following description when read in connectionwith the accompanying drawing, in whicl Figure l is a partial sideelevation of a liq sandblasting apparatus for carrying out method of theinvention;

Figure 2 is an enlarged partial section of the discharge end of theapparatus, and

Figure 3 is a transverse section on the line 3-3 of Fig. 2.

Fig. 1 illustrates a liquid sandblast gun or the type more particularlydescribed and claimed in the patent to Tirrell No. 2,200,587. As shown,the apparatus comprises a liquid blast gun formed by an elongatedhousing or casing it having a ban i grip H at its forward end and an armrest ii. at its rearward end. Liquid such as water under high pressureis supplied to the gun through a hose I3 and flow of liquid may becontrolled by a valve having a handle It. When the valve is open, liquidwill flow at high velocity through the gun and through one or moreinternal nozzles carried by the housing it. As seen in Fig. 2, two suchnozzles are employed, one of which, indicated at E5, discharges a highvelocity jet of water through a relatively enlarged space into thesecond nozzle to which is aligned with and of slightly larger diameterthan the nozzle l5. Abrasive material may be added to the liquid jetbetween the two nozzles through a supply connection I! which may beconnected to a source of abrasive such as a flowable mixture of sand andwater, as described more fully in the Tirrell patent. Passage. of thewater jet through the space between the nozzle-s will create vacuum todraw the abrasive material into the jet to mix therewith. If desired,air may be added to the liquid stream prior to entrainment of theabrasive material through a valve nipple it, :as described in theTirrell patent. It will be understood that any other desired type ofliquid discharge apparatus such, for example, as that particularlydescribed and claimed in the patent to Smith No. 2,040,715 could beemployed equally well according to the invention and that addition ofthe abrasive material to the liquid stream could be omitted if desired.

According to the present invention, I have found that the stream or jetof liquid either with or without abrasive material suspended thereinwhich is discharged by the nozzle it tends to break-up within arelatively short distance of the nozzle so that it cannot be usedeifectively for cleaning or cutting purposes except at relatively shortranges. According to the present invention, this breaking up of thestream or jet is minimized and delayed by the addition of air to the jetshortly before its final discharge. I have found that the addition ofair at this point is highly effective even though air has previouslybeen added to the jet through the valved nipple It, as described in theTirrell patent.

As shown, an auxiliary nozzle indicated generally at It is attached tothe discharge end of the nozzle to in alignment therewith and providesfor the addition of air to the stream or jet between the two nozzles. Asbest seen in Fig. 2, the nozzle 5 is formed by an outer sleeve 2! whichmay be threaded onto the end of the nozzle structure it and whichcarries an internal nozzle The nozzle is aligned with the nozzle l6 andhas a slightly larger bore than the nozzle [6 to receive the jet ofliquid therefrom. A spacer ring 23 is mounted between the ends of thenozzles 22 and it to hold them properly spaced apart and is of largerdiameter than the bores in the nozzles. To provide for the addition ofair to the stream, the ring 23 is formed with a series of air inletopenings 24 and is under-cut on its exterior surface to provide anannular space communicating with atmosphere through openings 25 in thesleeve 2|, With this construction, the nozzle 22, which may be subjectedto a certain amount of wear, may easily be removed and replaced asrequired.

In operation, as the liquid jet passes from the nozzle I6 through thesleeve 23 into the nozzle 22, it will create a partial vacuum in thesleeve 23 to draw air in through the openings 24 and 25. This air willbe entrained by the liquid jet and will be mixed therewith in the travelof the jet through the nozzle 22 so that the stream as finallydischarged comprises a mixture of liquid and air with the possibleaddition of abrasive material. While the exact reasons are not entirelyclear, it has been found by actual experiment that this stream will staytogether in the form of an unbroken jet and will not fuzz or producespray for a much longer distance then jet produced without employing thepresent invention. The efiects are equally noticeable even though airhas previously been added to the liquid through the valved nipple 18 sothat an effective jet can be thrown for a much longer distance with thepresent invention than with ones of the type shown in the Smith andTirrell patents or with a plain liquid nozzle.

It has further been found that the addition of an excessive quantity ofair between the nozzles l6 and 22 will cause the stream to break-up intoa spray very rapidly. This action occurs, for example, when air issupplied through the openings 24 under a super atmospheric pressure.Experiments have indicated that supply of the air under atmosphericpressure in substantially unrestricted quantities produces optimumressults. The size and number of the air inlet openings 24 and 25 may becontrolled by design to insure the introduction of the proper quantityof air into the liquid stream. It is also important that the nozzle 22be slightly larger than the nozzle It to accommodate the increasedvolume due to the addition of air, but that it be not too large or airwill tend to flow into the nozzle counter to the liquid stream to assistin satisfying the partial vacuum produced in the sleeve 23. The nozzle24 should, therefore, be of a size such that it will maintain the jetconfined without tending to compress it.

While one apparatus to carry out the method of the invention has beenillustrated and described, it will be understood that this is notintended as a definition of the scope of the invention, reference beinghad for this purpose to the appended claims.

What is claimed is:

1. The method of projecting abrasive material with liquid whichcomprises projecting the liquid in a flowing stream, adding abrasive tothe stream to mix therewith, thereafter adding air to the stream at itsperiphery, and maintaining the stream and added air confined for alimited distance after the addition of air to the stream.

2. The method of projecting abrasive material with liquid whichcomprises projecting the liquid in a flowing stream, adding abrasive tothe stream to mix therewith, projecting the stream through an enlargedspace containing air at substantially atmospheric pressure so that thestream will entrain air from the space, and confining the stream andentrained air for a limited distance posterior to said space.

3. The method of projecting liquid in a substantially unbroken jet whichcomprises projecting the liquid in a high velocity jet, adding air tothe periphery of the jet adjacent to its point of projection, andmaintaining the jet and added air confined for a limited distance afterthe addition of air to the jet.

ROY L. LUCE.

REFERENCES CITED The following references are of record in the

